Sorting equipment



April 17, 1962 G. HlRscHl-ELD ETAL 3,029,944

SORTING EQUIPMENT Filed Oct. 17, 1958 rl as INVENTOR. G. HIRsCHFELD-w. HINZ-H ITZSCHE I 3,029,944 Patented Apr. 17, 1962 ice SORTING EQUIPMENT Gerhard Hirschfeld, Berlin, Werner Hinz, Berlin-Neukolln, and Hanspeter Fritzsche, Berlin-Friedman, Germany, assignors to international Standard Electric Corporation, New York, N.Y., a corporation of Delaware Filed st. 17, 1955, Ser. No. 767,902 2 Claims. (Cl. 209-1115) This invention relates to automatic sorting equipment, capable of distinguishing between picture post cards and envelopes, and is an extension of the invention described and claimed in our copending application, Serial No. 726,405, filed April 4, 1958, for Article Sorting Control Apparatus. v

In the copending application, an automatic sorting system is described which has particular utility in the sorting of mail. The object of that system is to take mail in random order, separate the envelopes of unusual size, detect the position of the stamps on the remaining envelopes, and to separate the envelopes accordingly.

T he first operation, of separating mail of unusual size, is accomplished simply by positioning each of the envelopes, in succession, in front of a battery, or bank, of photocells. The cells are arranged so that an envelope, of standard size, blocks a predetermined number of cells from ambient or directed light. These cells, therefore, produce energy which is indicative of a standard or an irregularly sized envelope. The energy is utilized to operate a routing switch for separating the envelopes, carried by a conveyor belt, in accordance with a size classication.

The second operation, that of detecting the location of the stamp on the envelope, is accomplished by scanning four Ilengths or areas of the envelopes.

if it is assumed that the stamps were affixed to the upper right-hand corner of an envelope, and that the envelopes arrived in random order, then the stamp may be found in one of four positions, depending on the position of the envelope. The envelopes are conveyed on a longitudinal edge to the scanning station. If the envelope is rightside up, then the stamp may be either in the upper right corner of the righnhand side of the envelope or the upper right corner of the left-hand side of the envelope. The right and left-hand sides are arbitrary designations given to the respective sides as viewed in the direction of motion. If the envelope is wrongside up, i.e., the flap on bottom, then the stamp lmay be found in the lower left corner of the right-hand side or lower left corner of the left-hand side of the envelope.

The position of the stamp is determined by scanning or detecting devices located appropriately to scan the respective lengths of envelopes. The scanning means is effective for a length less than half the envelope, since the stampV is assumed initially to be aixed to the upper right corner of the envelope.

The position of the stamp is detected as a result of the difference of light rellectivity of the stamp as compared with that of the envelope. This difference is exaggerated when the envelope is white and the stamp is a dark, at color.

The mail is then routed by switches which are responsive to the outputs from the scanning means.

Although the invention described and claimed in the copending application is eminently well suited for sorting envelopes, it is not satisfactory for sorting picture post cards. In many instances, the color or colors of the picture are similar to the colors of the stamp and the scanning means, disposed and described above, is incapable of distinguishing the stamp.

Accordingly, it is an object of this invention to provide means for distinguishing between the opposite sides of an article such as a picture post card.

It is a further object of this invention to Yprovide a circuit operable in conjunction with the system described in the copending application for routing post cards to a predetermined destination.

lt is still a further object of the invention to provide a method for distinguishing between picture post cards and envelopes.

In accordance with an aspect of the invention, there is provided sorting apparatus including means for detecting the light reectivities of the central portions of opposite sides of a picture post card, and means for comparing the energies from the detecting means to determine the side having less reflectivity. This side would be the picture side. The output from the comparing means is preferably utilized to disable one side of the subsequent scanning means positioned to detect the location of the stamp. In other words, once it has been established which side of the card is bearing the picture, only the opposite side need be scanned for determining the location of the stamp.

The central area is scanned, first to avoid scanning the stamp which is aflixed to a corner of the card, and further, because in most post cards the central area is the darkest part of the picture.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawing, wherein the drawing is a block diagram of a complete sorting system.

Referring to the drawing, the mail arrives in random order at A and each of the articles constituting the mail is positioned on a longitudinal edge thereof, on a conveying belt, suggested by the arrow. The mail is moved through size-sensing station B, and depending upon whether the size is standard or irregular, is either continued on the conveyor belt or routed off the belt by switch C. The size-sensing station B is described in detail in the aforesaid copending application and generally above. For an understanding of this invention, it is sufcient to know that the station B comprises a plurality of photocells B1 aligned with oppositely disposed lightsources B2. When the envelope comes to rest between the cells and the sources, it blocks the light from a certain number of cells. The size of the envelope is, of course, a function of the number of cells blocked from the light.

The outputs from the cells B1 are applied to an evaluating circuit B3. The evaluating circuit is conventional and is designed to produce an output in response to a predetermined number of input pulses. For example, the circuit may be a counter, and each photocell which is blocked may deliver a pulse. Upon receiving a predetermined number, the counter would deliver a pulse to the routing switch C. lf the count is selected to indicate to indicate an over-sized envelope, then the routing switch would be operated to direct the envelope off the conveyor belt in response to such count. The pulse from the counter may be of suiiicient duration to hold the switch until the envelope has been deflected by it. Other alternative embodiments which will be apparent to those skilled in the art may be utilized to perform this function. An example of a suitable evaluation circuit may be found in FIG. 3 of the copending application. This evaluation circuit is of the diode type, the inputs of which are derived from photo transistors P10-P60. These photo transistors perform the equivalent function of photocells B1.

The envelopes are then successively conveyed to the picture-detecting section of the equipment, comprising energy detectors I and II. The detectors may be photocells, light-responsive transistors or the like, which produce electrical energy of varying magnitude, in correspondence with the variations of light applied thereto. 'il-ie intensity of iight applied to the detectorsV depends, of course, on the reectivity of the viewed surface.

The envelopes are successively brought to rest between the detectors I, II at a position suggested by the dashed lines. In this position the detectors view the central portions of the opposite sides of the card. The means for stopping the envelopes may be conventional and, in the interest of simplicity, has not been illustrated. For example, the stopping means may be an edge-detecting photocell or microswitch, with timing means to start-up the conveyor after a predetermined stoppage time.

The detectors I, II are connected, respectively, over arnplitiers V1, V2, filters Al, AF2 and storage devices Sp1, Sp2 to an evaluating circuit R. An example of an amplier suitable for use in box V1 and V2 may be found in the copending application. It consists of V1 which is shown in detail within box El. The iilters AE1 and AF2 can be amplitude filters of a known variety. A simple LC tilter would adequately perform the function. Sp1 and Sp2 are well known trigger circuits or dip-flops. An example of suitable circuits are shown in FIG. 2 of the copending application and are likewise designated as Sp1 and Sp2.

The evaluating circuit may be a conventional circuit for either comparing the magnitude of the amplified energies against each other or against a reference source. For example, the reference source may be a pair of conducting rectiers connected to the respective detectors and the energy from the light side of the card may be suicient to cut-off the associated rectifier. Other suitable evaluating circuits will be apparent to those skilled in the art.

The output side of the evaluating circuit is connected to the scanners L and E, which are described in detail in the copending application, and also to routing switches W1 and W2.

The output energy from the evaluating circuit is such as to cnt oic the scanner on the side of the picture, and to operate the switches in accordance with the position of the stamp on the card. The sorted cards are delivered to hoppers N and M.

While the foregoing description sets forth the principles of the invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation of the scope of the invention as set forth in the objects thereof and in the accompanying claims.

What is claimed is:

l. Sorting equipment for distinguishing between picture post cards and envelopes, comprising edgewise conveying means, a pair of light energy detecting means for scanning both sides of cards and envelopes on said conveying means to detect whether a picture exists thereon, a second pair of scanners for scanning both sides of cards and envelopes to detect a stamp thereon, said second pair of scanners located after said pair of light energy detecting means along said conveyor, and an evaluation means coupling said pairs of light energy detecting means and scanners for rendering one of the pair of scanners inoperative in accordance with the detection of a picture by a corresponding one of said first pair of light detecting means.

2. The equipment according to claim l, and further comprising routing switches mounted along said conveying means for selectively routing said picture cards and envelopes ot said conveying means at predetermined destinations, means connecting said routing switches to said evaluation means, and said routing switches being opcrative in response to the output of said evaluation means.

References Cited in the tile of this patent UNITED STATES PATENTS 

